The present invention relates to an ultrasonic welding device for mounting of wire ends or wire loops on terminal lugs, particularly on terminal lugs of lamellas of drum-shaped commutators for rotatable electrical machines.
Devices of the above mentioned general type are known in the art. The German document DE-OS 2,739,730 discloses a method of producing an armature for dynamoelectric machines, in which the conductor parts of the armature winding are electrically and mechanically connected with commutator lamellas by ultrasonic action. The conductors are mounted either on the terminal-side ends of the brush running surfaces or for the purpose of increasing the contact surfaces, in the recesses of the lamellas. A further method for producing an electrically conductive and mechanical connection of the armature winding wires with the lamellas of a commutator is disclosed in the German document DE-OS 3,017,426. Here also the connection is produced by ultrasonic welding, and the commutator lamellas are rolled on the contact surfaces of a sonotrode. When this method is used in connection with hook lamellas, the hooks which receive the winding wire loops are bent during rolling by the sonotrode in direction to the lamellas and welded on the lamellas. A sonotrode is also known for cold pressing welding of metallic workpieces with the use of vibrations performed parallel to the contact surface of the workpiece. The end of the sonotrode, for example a wire, which is brought in contact with the workpiece, engages the workpiece in the swinging direction of the sonotrode. This method is disclosed in the German document DE-AS 1,228,494. For producing of wire grids the wires which are located under the wires engaged by the sonotrode device can be inserted in corresponding groove recesses of an anvil. In accordance with a further embodiment, a cylindrical knob is welded on a flat plate, and the plate is held during the welding process inside a bearing point in its position.